Field of the Invention
The present disclosure relates to a light emitting device which uses a semiconductor light emitting element, and a method for manufacturing thereof.
Description of the Related Art
A semiconductor light emitting element (or a light emitting diode; LED) has the following features in comparison with an electric light bulb: a) a response speed for turning on and turning off is faster, b) a length of life is 50th to 100th times longer, and c) an electric power consumption is about ⅓ to about 1/15. By applying such features, a light emitting device which uses the semiconductor light emitting element is utilized in a very wide range of fields such as a back light of a liquid crystal display, an outdoor full color display, a toy, a general lighting, a light source for reading and/or writing of an optical recording medium, a light source for optical communication and the like. It is also expected to facilitate energy saving by using the LED, and currently, study and development of the LED is energetically performed, aiming at raising luminance, efficiency or the like. In particular, relating to the light emitting devices for automobile use, and for general lighting use, the demand for a high luminance, a high efficiency and a low electric power consumption is very strong.
Under such circumstances, an invention for enhancing a light extracting efficiency from a light emitting device is described in JP2012-124219A. In JP2012-124219 A, there is disclosed an invention relating to a semiconductor light emitting element which has a semiconductor laminated structure having a light emitting layer placed between a first conductive type layer (an n-type semiconductor layer) and a second conductive type layer (a p-type semiconductor layer), and in which a light is extracted from the first conductive type layer side of a light emitting layer. In the light emitting device according to JP2012-124219A, a surface (a light extracting surface) of the first conductive type layer, which surface is opposite to another surface which contacts the light emitting layer is roughened to suppress total reflection of the light emitted from the light emitting layer, resulting in enhancement of light extracting efficiency.
As described in the JP2012-124219A, the light emitting device in which the light extracting surface of the first conductive type layer is roughened might be one preferred embodiment for enhancing the light extracting efficiency.